Process for forming dental structures.



UNITED STATES PATENT OFFICE.

JOHN A,.- LEINTZ, or PHOENIX, ARIZONA TERRITORY.

J PROCESS FOR Fonmmeoznnr 'sr'n'ucrunssr To rrl lwhom, it may concern:

Be it known that I, JOHN A. LENTZ, a citi- .less labor and expense, and with more perfect results than heretofore.

- More specifically stated, my objects are, first, to facilitate and expedite the re roduction or duplication in gold, gold afioy, or similar substance of a variety of forms, such 3 as inlays, onlays, cusps, facings, tooth-crowns,

dummies, and other dentalstructures; secnd, to add and attach to any such reproductions in'the relation desired and simultaneous with the making OfSttld reproduction and by the same operation pins, porcelain carrying pins, bands, plates, crowns, clasps, special anchorages, and other-dental structures of gold, gold alloy, platinum, or similar substance; third, to'enable a plurality of operations, as mentioned before specifically, to be performed at one time and practically in one operation; fourth, to dispense with the use of solder in backing up porcelain facings, reinforcing-cusps, uniting-cusps,and bands, and

formanyothcrunions and restorations where solder has been heretofore used; fifth, to

facilitate the ada )tation' of the inner surface of the cusp of a s ell-crown to, the surface of the root to be crowned and of'a backing to a porcelain facing; sixth, to dispense with swaging in a great many cases; seventh, to enable the employment of scrap gold in many places where gold in mere expensive form has been used heretolorc. ll accomplish these objects by the process herein de-.

scribed and illustrated in th(LaccoInpanying drawings, in.whicl1----- Figure 1 is a side elevation, partly in section, of the nlolding-machino used in carry ing outmy process. Fig. 2 is a plan of the machine. Fig. 3 is a perspective View of Specification (if Letters Patent. Application filed Anguit so, 1905. Serial No. 276.428;

then properly contoured.

Patented Oct. 23, 1906.

a gold band used in forminga gold crown, Figs. .4, 5, and 6 are views illustrating differ ent steps of my improved rocess.

I have illustrated and wi I explain my process applied to makinga gold shell-crown.

In the drawings the gold band 6, made in a suitable manner, is fitted to the cervix of the tooth 7, whichhas been properly prepared for the reception of a crown. The band is With the hand in place 011 the tooth a suitable impression material 8, such as modeling compound, i forced into the band and the brought together,

forcing the compound against the root within the band and against the occluding surfaces of the opposing teeth 9. The jaws may be opened and closed several times in such various positions as thc'jaws mayLassume', and by carving orforcing away any interfering compound the surface thereof is made to conform as closely as possible ,without interference to the opposing occlusal surfaces in all of the various positions that the aws may naturally assume. The band,'with compound in place, is now removed-from the root, and the cavity formed by the root: filled with a'batter of fyrite 1 1 orsimilarniaterial having the pro perties of an investment-as well as a molding material and adapted'to withstand high temperatur es. When the. l'yri to is sufficiently hard to maintain the relation of band and compound, the lateral excess of modeling compound is cut away till flush with the sides of the band and anyfurther carving done which in the judgment of the operatormay add to the artistic effect or practical uscof the finished crown. The band, filled with fyritc or similar substance; is now placed in the cover-cu {12, also filled with same u'iatcrial, and the band is forced into the same approximately to its occlusal edge. When sufliciently hard, the fyrit'e ll which shallhereinafter be referred to as investing n'iatcrial, is trimmed smooth from the edge of the cup to the occlusalodgc of the band, leavingthc modelingcompound cusp 10 projccting,"asshown in Fig. 5. Like investment material iii/a plastic state is then placed in the base-cup 13 and the two cups are brought together, as shown in Fig. 1, and a clamp l4,'securcd to base-plate 15., is brought over the. end of'the handle 16 of the (mvcr-cup, so as to hold the two-cups together until the invcstmentmaterial in base-"cup has hardened, after which cover-cupprojects rearwardly of the pivotal egnnectioriwith the standards and is adapted to engage with the detent-bar 19, so that the covercup may be held separated from the A base-cup,- as hereinafter explained. A restwhen it is desired to fill the same.

bar'20 provides a support for the cover-cupv Portions of the space'which it is undesirable to fill with the metal to be used for formation of the cus are also filled with investment material. f the natural root is so short as to make it undesirable to have the inner surface of cusp in contact with it, I fill the inside of band with investment material and carve to any desired depth or form. I now carve away enough investment'from either or both cups in the manner shown in dotted lines to allow for esca e of the excess of metal, but without encroaching on the'band or the edge of the mold of the base-cup. In special cases, however, I sometimes cut gateways, connecting mold with the space provided for excess of metal.

One or more buttons of gold or gold alloy, as desired, and somewhat in excess of the actual amount required to fill the space forthe cups.

merly occupied by the modeling compound '10, are placed in the mold in the base-cup.

If desired, flux may be a plied to the exposed portions of the band The cover-cup is held by the detent-bar at any desired distance above the base-cup, as shown in Fig. 5f

In this position the base is suitably sup orted over a Bunsen-burner flame, w1ich,{ through the apertures 23, plays up around WVhen the investment has become thoroughly dry and when the band has become sufficiently hot, but without fusing, additional heat by means of a blowpipe, if re-- uired, is applied to the gold button until it. uses, when the cover-cup is. brought down upon the base-cup, as shown in Fig. 6, when the fused metal 22 is forced into the covermold, thereby completing-the desired struc: ture, and heldin place, and heat is. withdrawn and case allowed to cool. Other methods of applying and distributing the heat are used in different cases; but the essential fea' ture is to have the band-in cover-cup heated to a sufficiently high temperature without melting and when in this condition to bring it in contact with the molten metal in base- Vhen the case is sufficiently cool, the crown is removed and will be found to have the cusp correspond to the form of the mold securely united to the band. In the usual way excess around the line ofjun'cture between cusp and band is removed and the in'g porcelain parts or porcelain-carrying 7o metals into portions'of the mold, by varying the size and form of the base and cover cup, by varying the means and methods of applying and distributing heat, by varying the use and distribution of flux the same process described in detail with respect to gold shellcrowns is likewise applicable to the making of inlays, onlays, other crowns, bridges, artificial dentures, and other dental structures and certain parts of the foregoing, as well as the performance of a plurality of such operations at one time.

Having. described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The herein-described process of maki metal-containing structures which consists o forming a mold of a predetermined part of such structure in suitable molding, investing,

heat-resisting material contained in one of the registerable parts of a separable moldingmachine, of placing a previously-formed part of such structure in the other registerable part of the molding-machine, of then fusing in the mold sufficient metal to form with the previously-formed part the completed structure, of then bringing the fused metal into contact with the formed part and allowing the same to solidify while in such contact.

2. The herein-described process of forming certain-dental structures, which consists in embedding in material contained in one of the parts of the molding-machine one of the parts of the dental structure; then taking an impression in another part of the moldingmachine in like investment material of the form of the other part of such dental structure and after the material has hardened separating the parts of the molding-machine, then forming up the investment material for casting, then fusing material in one of the parts of the molding-machine to form the other part of the dental structure, then bringing the non-fused portion into engagement with the fused material; and then permitting the fused material to solidify.

- part of the m'old are united; and then allow vIn witness that I claim the fore oing I have hereunto subscribed my elmet is 22d day of August, 1905.

' JOHN A. LENTZ.

tion of the meld 'sufilcient metal to fill the entire mold when its parts are caused to re ister: of then causing the parts of the mol d to register, wherebythe fused metal in the.

Witnesses mold and the heetedunfused metal forming I G. E. HARPHAM,

ing the fused portion to solidify. EDMUND A. STRAUSE. 

